DOLIOSAURUS MODESTUS. 499 



and the arms are very large, strongly keeled, acuminated, and some- 

 what raised, giving a rather rough appearance to those regions. The 

 tail is broad, depressed, and tapering. 



Loc. Deserts of the Gila and Colorado Rivers. 



2. DOLIOSAURUS PLATTRHINOS, Grd. 



SPEC. CHAR. Cephalic plates small. Occipital spines of moderate 

 development. Submaxillar shields stout : posterior ones subconi- 

 cal. Auricular apertures generally extant. Mental scales small, 

 subequal, with two longitudinal and very distant series of slightly 

 larger ones. Pectoral scales moderate, subcarinated, and acumi- 

 nated. One series of pyramidal scales at the periphery of the 

 abdomen. Abdominal scales moderate, smooth. Femoral pores 

 few, conspicuous, and distant, encroaching upon the interfemoral 

 region, though not in a continuous series. Brownish-olive above, 

 transversely maculated with black ; beneath yellowish, unicolor. 



SYN. Phrynosoma platyrhinos, GRD. in Stansb. Expl. Vail. Gr. Salt Lake, Utah, 

 1852, 361 & 363. PI. vii, fig. 1-5. 



OBSERV. This species has a more spinous appearance than D. 

 mccalli and D. modestus, without, however, approaching to anything 

 like the species of Phrynosoma and Batradiosoma. On the other 

 hand, the pyramidal scales at the periphery of the abdomen are but 

 moderately developed, and those on the anterior region of the chest 

 much less conspicuous than in D. mccaUi, the abdominal scales being 

 rather smaller than in the latter species, and smooth, whilst the men- 

 tal scales are more developed, and the series of larger ones occupy a 

 more lateral and backwards position, since it extends likewise over 

 one fold on the side of the neck. The tail is of moderate development, 

 depressed, and tapering. 



Loc. Valley of the Great Salt Lake of Utah. 



3. DOLIOSAURUS MODESTUS, Grd. 



SPEC. CHAR. Cephalic" plates very small. Occipital spines small. 

 Submaxillar shields stout : posterior ones subconical. Auricular 



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